mered 5f2.00 tion Suppose that S1 and S2 are empty stacks and al, a2 and a3 are objects. What do the stacks contain after executing the following sequence of operations? Sl.push(a2); S1.push(al); S2.push( a3); S2.push(Sl.pop(); S2.push(Sl.peek(); Select one: O a. Si=[] and S2= [] O b. S1=[a2) and S2=[a3 al,a2] O c. Sl= (a2, al ] and S2= [a,3,a3, al] O d. NONE